Variable-speed transmission mechanism.



A. LATHAM. VARIABLE SPEED TRANSMISSION MECHANISM.

APPLICATION FILED FEB. 26, 1906.

Paisanteol Oct. 6, 1908. SHEETSSHEET 1.

A, LATHAM.

VARIABLE SPEED TRANSMISSION MECHANISM.

APPLIUATION FILED FEB. 26, 1906.

Patented 0ct.6,1908l 7 SHEETS-SHEET 2;

A. 'LATHAM.

VARIABLE SPEED TRANSMISSION MECHANISM.

. APPLICATION FILED PEB.26,'1906.

75 Patented Oct. 6, 1908. TSHEETS-SHEET s.

lllll llll illll l A. LATHAM. VARIABLE SPEED TRANSMISSION MECHANISM.

APPLICATION FILED FEB. 26, 1906. v990, 75, Patented 0013.6,1908. 7 SHEETS-SHEET 4.

A. LATHAM.

VARIABLE SPEED TRANSMISSION MECHANISM.

Patented 0013.6,1908.

7 SHEETS-SHEET 5.

APPLIUATION FILED EBB. 26, 1906.

A. LATHAM. VARIABLE SPEED TRANSMISSION MEGHANISM.

APPLIOATION FILED FEB. 26, 1906.

Patented Oct. 6, 1908,

7 SHEETS SHEET 6..

a Q I S A 1 x V w I A. LATE-1M. VARIABLE SPEED TRANSMISSION MECHANISM.

00 7 0 Tv QUE 1E L on dS mn w a P R 0 9 1 2 L E D E L I r. N o I T A NV I L P. P A

,nnrrsn eras ng rarities enrich.

ALBERT LATHAM, OF WALTHAM, MASSACHUSETTS, ASSIGite; OF ONE-HALF TO JAMES W.

N OURBOURN,

OF SOMERVILLE, MASSACHUSETTS.

VARIABLE-SPEED TRANSMISSION EECHANISM.

Specification of Letters Patent. Application filed February 26,1906. Serial No. 303,113.

Patented Oct. 6, 1908.

To all whom it may concern;

Be it known that I, ALBERT LATHAM, a citizen of the United States of America, resident of Waltham, in the county. of Middlesex and State of Massachusetts, have inand useful Improvements vented certain new 1n Var1able-Speed Transmission Mechanism,

of which the following is a full, clear, and l exact description. k

his invention relates to improvements in variable speed transmission mechanism, such as most extensively employed in automobiles,-and elsewhere used,of a kind including a transmission shaft, another shaft having connection with the d and variable speed and reversing gearing in sets, any one of which nectcd to constitutes proper speed and desired direction between the shaf automobile, or to other part or mechanism to be variably or reversibly driven.

he new mechanism of this invention is characterized by provisions for, and capa bility of, the utmost flexibility in theoporation, that is the starting of the motion of t e transmission shaft, after the latter has been at rest, and the changing of its driving motion from one speed to another, either faster or slo var, or in a reversed direction, are gradual, and yet sutiiciently rapid,-all violence, or jolting or gear-toothgrinding, or other destructive action, being absolutely avoided, which avoidance as known is not the case generally with sliding-gear speed changing and reversing transmission mcchauism. or a transmission mechanism compris- .ing clutches constructed increly with interengaging and disengaging teeth. 1

The-invention in part consists, in a variable speed transmission mechanism, transmission shaft, a ccuntershaft and means for driving it, clutch members on the transmission shaft and normally free for rotation independently thereof, variable speed gearing, and also generally a reversing gearing, in sets, connecting the countcrshaft and said clutch members, follow, clutch devices carried by and po'n-rotative relatively to the transmission shaft, and eacl comprising a frictionally engaging shoeor' member, and a locking member, and for coaction with the respective first named clutch members, means riving power ay ev tgiitch con right hand end of Fig. 1, t1

tration.

for placing any one of the several friction shoes into and out of engagement with the respective clutch member with which it coacts, and means for additionally placing the locking member of the given clutch device m into engagement with its clutch member, and for withdrawing it therefrom.

The invention furthermore consists in Vahe construction of parts, a l substantially as hereinafter fully described and set forth in the claims.

he mechanism while embodying the essentials of this invention may be organized so as to provide for a greater or less number 0 speed changes for the transmission shaft a reversed driving thereof at, any desired speed and in the illustrations and description of the'mechanisni here provided, provision is made for a comparatively high and intermediate and a comparatively slow forward driving of the transmission shaft and for a slow reversed driving of such shaft.

In the accompanying drawings,-Figure g is a side elevation of the incascd transmission mechanism, a'poltion of the engine, or primar 7 motive power, shaft, and the compensation gearing through which the divided axle for an automobile may be driven. 35 Fig, 2 is a plan view showing, partly in section, however, the connection of the transmission shaft with the compensation gear.ing,-the latter comprising no especial novelty. Fig. 3 is an elevation as-sicenat the 1e engine shaft being represented in cross section. Fig. 4' is a sectional elevation of the variable speed transmission mechanism, the inclosing casing being shown in vertical section as taken on the line 44, Fig. 3. ig. 5 is substantially a horizontal longitudinal sectional view taken, on the line Fig. 3,*a left hand portion of the by full lines in plan view,-fragments, however, being broken away for clearer illus- Fig. 5 is. a horizontal sectional view of the right hand portion of the mechanism, some of which is included in Fig. 5.

shaft,

a perspective view showing separated relations,

' line 9-9, Fig. 5. Fig. 10 is a side elevation and parallel with the shaft A, both said mg being constructed at its end with suitable power shaft in longitudinal alinement with remembered that the clutch member a and the clutch-member back, and each member clutch rim 16.

' the circular clutch member 6 is made unitary lar cross sectional view taken on line '77, Fig. 4, and more particularly showing the gearing for the reversed driving. Fig. 8 is the parts, in ofone of the clutches. Fig. 9 is a vertical cross sectional view on of the mechanism which controls the positions and conditions of all of the clutches, whereby none thereof may constitute a medium of connection between the power driven countershaft and the transmission shaft, or whereby any of the clutches may be set.

Similar characters of reference indicate corresponding parts'in all of the views. In the drawings, A represents the transmission shaft and B the countershaft above shafts and the gearing clutches and devices appurtenant thereto being inclosed within a casing C made in separable sections detachably connected together by bolts,-said casbearings for the support of the shafts.

D represents the engine shaft or motive the transmission shaft, and as represented in Fig. 5 has the universally jointed section 10 thereof which is adjacent and extended through the end of the case C made of tubular or sleeve like form, fitting through the one end journal bearing 12 and receiving for rotation independently therewithin the extremity of the transmission shaft A. The said portion 10 of the engine shaft at its extremity which is extended within the 'case is constructed with a circular cup shaped combined positive and friction clutch member a, unitary with which and with the shaft section 10 is a spur gear wheel 14, it being the gear. wheel 14 may rotate as one with the engine shaft and independently of the transmission shaft.

l nseparation at suitable intervals on in termediate portions of the shaft are combined positive and friction clutch members I and c and within the casing near the end of the transmission shaft farthest from its end in bearing within the engine shaft is a fourth circular combined positive and frie lion clutch member (Z.

All of the combined positive and friction clutch members are of cup shape, two thereof being shown in sectional view in Fig. 5, and each comprises a' portion having the form of an annulus, and indicated by the numeral 15, such portion being herein referred to as further comprising the annular flange or As the mechanism .is organized in detail,

with. a spur gear wheel 17 which is located next thereto and riveted to its back, but the l clutch members 0 and d instead of being edgewise ad acent the gear wheels 18 and 15 which are as one therewith, are surrounded by the gear teeth and are made as chambered or cup-like bodies for the gears 18 and 19.

The countershaft D above and parallel with the transmission shaft has thereon gear wheels 24, 27, 28 and 29, meshing respectively with the clutch member gears 14, 17 and 18 and with an intermediate gear 21 on a stud shaft 22 on which is a pinion 23 which in turn meshes into the spur gear wheel 19.

The gear wheels 21 and 14 are of equal 'size, the gear wheel 27 is somewhat smaller than the 5 air wheel 17 and the gear wheel 28 is of still further decreased diameter than the gear wheel 27, while the gear wheel 18 in which the one 28 meshes is proportionately larger than the one 17. It is thus seen that-power from the engine shaft through gearing 14, 24, driving the countershaft ll at the same speed as the engine shaft, will impart a rotary motion to the clutch incmher a. in unison with the engine shaft speed. will impart a slower motion to the clutch member Z), will impart a still slower motion rotatively to the clutch member 0 and will impart also a very slow rotary motion in the reversed direction to the cluth member (I.

For each of the several clutch members (I. 7), c and d, is a fellow clutch device which is carried revolubly and as one with the transmission shaft (when the laiter rotates) and for each of these coacting or fellow clutch devices is a setting or clutch closing means so that selectively any of the circular clutch members free of the transmission shaft (but only one thereof, however, at one t me) may be put in clutch with and cause a driving of the transmission shaft and the vehicle or other machine with which said shaft is connected at the rate of speed cori'cspoluling to that of the member which is in clutch.

The coacting parts in each set of clutches are constructed and organized for two characters of clutch engagements,-lirstly a frictional engagement only, and secondly and additional thereto, a. positive locking engagcnmnt wherebyit becomes possible to ini tially set the clutch to acquire anygivcn speed or driving of the transmissil'm shaft forwardly or reversely by the engagement only offrictiomilly binding parts and lhcn to, at pleasure, render the same clutch in condition for the positively interlocking parts thereof to automatically come into engagement.

The details of construction whereby the capabilities last above referred to are ful filled, are illustrated in Figs. 5, 8 and W most particularly, and the description thereof now to be given in respect of one of the clutches is applicable to all of them.

Each of the clutch members 0, I), (a and (Z has in its back 15 a socketI-it) axially parallel with the transmission shaft. Adjacent each of the circular clutch members is a support for the coacting or fellow clutch devices, the

sa ine comprising a hub 32 fitting over the transmission shaft which is made with the. longitudinally continuous spline ribs 33 l which are especially provided for the sliding but non-rotatable engagement of the clutch operating collars (hereinafter to be referred to}? in relation'to the transmission "shaft. I Each of said hubs has a socketed boss 34 retherein a plug 35 endwisc reccs. d to d e'the spline rib 33 of shaft A an enteri. a socket 36'made'transversely within the side of the shaft; and said interlocking plngfi'is confined in place .by the screw plug 37 threading into the soclreted boss 34.

. lhe hub 32 of the aforesaid support has the radially extending members 40 and 42 indies-with each other and the radially ex- 31 fended member 44 n right angles to the line of the members 40 and 42, the ortion 44 be- ,ange ongated in a line paralle with the axis of shaft- A and made with a circular bore 45 extending from end to end therethrough.

"the member 40 of the clutch device 5:5 and are made witlrbeveled corners,

as represented at 56. The other end of the portion i2 of thesupport has a recess 57 thereacross in a line parallel with the trans,- mission shaft, the same being intersected at right angles by another recess 58 in which fit the reduced extremities of'the, friction shoes. Said recess 57 forms a slideway for the friction shoe expanding bar. 60 soon to be more particularly described. In the tbore 45 of the aforesaid supporting structi'zre is a longitudinallyslidable locking bolt (51 which is made with a solid inner end and otherwise tubular opening to its outer end and formed with. an internal screw thread.

1 (See-Figs. 5 and 9.)

".Lach of the clutch devices has for action adjacent thereto and'in conjunotion therewith a collar f deeply annularly grooved, and while free for'endwi'se play along the transmissiiin shaft which it surrounds, it-

h ave-no rotary movement independently (if such shaft because of its-engagement with.

tire/aforesaid splinerib 33. Said collar car- 'lougitudinally extending stud 651mm head or a rlock enlargementfii) engaged.

within the tubular bolt 61 and in contact against a spiral spring 67 within the latter and in cndwise bearing against the solid inner endof the bolt. An annular plug 68 screw engaging into the threaded orifice of the tubular bolt forms an abutment for the bolt head 66 and yet allows the stud to play endwise inwardly independently relatively to the bolt.

The bolt and alined stud are as far radially offset from the axis of the transmission shaft as is the aforementioned socket 30 in I 'the back of the circular clutch member, as definitely shown in Fig. 5, and in a manner indicated in Fig. 8. The aforesaid collar f carries, as a rigid longltudlnal extension thereof parallel with the'transmission shaft and alined with the aforementioned recess 5'1 in the end of the member 42 of the support, the shoe expanding bar 60, the end of which is beveled or made of wedge shape and the end portion of which plays in'the aforementioned recess 57; and when the collar is moved in a proper degree towards the back of the circular clutch member, the free and expand the friction shoes setting them in their bind against the inner surface of the, clutch member flange.

a o a l Dlametricall-y opposite but ranging parallel with the friction shoe expanding bar (30 is a friction shoe contracting bar 70, the

same having an engagement in suitabletimc and during the endwise movement of the collar f which carries it with the aforementioned lug 53, with the result of applying through such lug a leverage to swing the friction shoes inwardly and free from bind against the clutch member rim.

It is noted that the points of engagement between the widened end portions 72 of the bar 70 and the points of engagement between the widened end portion of the bar 60, and

end portion of the bar 60 will enter between the free ends of the friction shoes are in 7 different planes or locations so that when the collar is forced to move the'bars t0- Wards one of the circular clutch members sufficiently far to bring the shoe expander into engagement between the ends of the I shoes, a shoe contrafcting bar will havepasscd inwardly beyond and out of engagement with the aforesaid lugs 53, and vice 'versa; and in Fig. 8', the relations of the parts arennderstood to be those when the collar f is niovedendwise away from. the clutch member, freeingthe shoes so that theyniay be contracted, the portions 72 of the contracting bar 70' being shown in the engagement with the lever lugs 52 to, positively inwardly swing the shoes.

The bars 60 and 70 are made with'their extremities of' maximum width and narrowed to the rear of such wide portions and ,the bars are longitudinally split'or slotted, asirepresented'at 75 and capable of adjustment, as may be accomplished by the abutting inner ends of screws 76 which oppo sitely penetrate the portions of the bar at either side of the slot 75.

The clutch mechanism per se shown and collar f at the left of the drawing corre' spondingly pertains to the other two clutches for the lowest speed and reverse driving,' the arrangement being such that when the left hand collar f is moved from its extreme leftward position to be free of the clutch of the' reversely driving gearing it approaches but does not necessarily come into touch with the lowest speed gearing; and a further movement of such collars of the right to bring the lowest speed gearing into clutch will carry such collar and the bars (30 and which had coacted with the friction shoes of the clutch for the reverse gearing further away to the rightward from such clutch. And so similarly the right hand collar may have an intermediate position between the clutch cases a and b so that neither of these parts are in clutch, or it may be moved towards the one to put in clutch further withdrawing the clutch operating parts pertaining to the other clutch therefrom.

It will be understood in the operation of any of the clutches that the collar to secure such operation may have two step like mo tions, the first from its intermediate, neutral or non-effective position sufficiently far to only set the friction shoes in clutch; and

the second and additional moveme t to force the bolt with a yielding pressure against the back of the clutch member so that in more or less of a rotation of such member the socket 30 thereof on coming around to registry with the bolt willpermit the latter under the reactionbf its spring (37, in compression between the bolt end and the end of the stud 65, to snap to interlock in the said socket thereby making the positive clutch engage ment in addition to the already acquired frictional engagement.

Peculiar to this mechanism, organized as shown, the same may be'run for any desired length of time while in frictional clutch thereafter for any desired period while in the additional positive or interlocked clutch and again back on the frictional clutch only for any of the desired speeds. And the controlling means for the collars is such that it will be impossible to change abruptly from one of the speeds to another widely different therefrom, but if running on the lowest speed the highest running speed may not be obtained until after the transmission shaft has been placed in clutch for the intermediate speed; and it is moreover impossible to change from either the highest or intermediate forward driving speeds to the reverse driving without first bringing the transmission shaft into clutch for the lowest forward driving speed. And as an example of a controlling mechanism for the various clutches actuating them through the sliding collars, reference is to be had to Figs. 1, a), and 10 in which are'shown a pair' of slides 80 and 82 in endwise alinement opposite and arallel with the transmission shaft, each iaving a forked arm 83 engaging one of the sliding collars within the annular groove thereof.

84; and 85 represent rock shafts arranged at the side of the mechanism and having their axes in parallelism and at right angles to the length of the transmission shaft, and these rock shafts have downwardly extending lever arms 86 and S7 engaging in rccesses SS in the respective slides 80 and 82. Each rock shaft 81 has a lever ailixed thereon comprising two arms 89 and J0 angular to each other, the arms of one lever being opposite and projecting to ards those of the other lever; andeach arm carries at its end a friction roller 92.

Centrally between and parallel with the rock shafts 84:, 85, is a short shaft or stud 93 having affixed thereon a cam fl-l and a pinion 95. The cam as shown in Fig. 10 has the form of an acorn, and according to the positioning thereof correspondingly imparts desired positions to the angular levers, the slides 80 and 82 and the collars f engaged thereby. A sector gear 96. is pivotal] y mounted for oscillation on .ihe exterior of the casing C and is in mesh with the aforcmentioned pinion 95. A controlling lever 97 pivotally mounted-on a suitable support by the link or rod 98 connects with the sector gear and said lever has its swinging movement alongside of an arcshaped plate which is edgcwise provided with properly arrai'iged notches for the engagement therein of spring detents 100 and 100", which are carried by the lever.

The form or design of the cam 91- and of the angular levers H8. 9!), and arrangcmci'it for cooperation of these parts, are such that the transmission mechanism may be entirely out of touch or have the clutch devices of one, and one only, pertaining to the gearing for a given direction and speed of driving either in frictional engagement or both frictional and positively interlocked engagement, all of the other clutches except the one selected and put in clutch being free or out of engagement. In the illustrations of this mechanism shown, the positions of the collai's f, are by the controlling mechanism such as to place in clutch the reverse slow co ers speed driving gearing for the transmission shaft, this clutchin being both of the frictlonal'and positive interlocked character; and this condition is determined by one of the detents 100 of the lever 97 being in the notch 101 of the arc-sha ed plate 99. When the lever is moved slig tly to the right so that the detent 100 enters the notch 102 the left hand collar of the mechanism and the bolt controlling part carried thereby will have positions such as to just withdraw the bolt for positively locking the clutch of the reversed gear, leaving the latter only in frictional engagement. Further movement of the controlling lever 97 to bring the detent 100 into thenotch a in the plate 99 insures an entire release of all of the clutches. A further forward movement of the lever whereby the detent 100 engages, in the notch 103 results in bringing the clutch of which member 0 is a part into frictional engagement only for the lowest speed forward dr1v-- ing; and when the detent moves into the notch 10%, the mechanism in the stated clutch is 1n positively interlocked condition, which may be followed by moving the lever to bring the detent into the notch 105 by insuring to the stated clutch its frictional engagement only, the positive, locking bolt for this clutch being withdrawn from its locking engage ment. Further carrying the lever to bring detent 100 into the notch "102 insures that all clutches a re bpen or released.

lVhen detent 100 moves into no'tch 107, the clutch for the intermediate speed gearing is in frictional engagement followed by the additional positive locking engagement when the detent enters notch 108, such. locking engagement being thrown out when the detent enters notch 109 which leaves the stated clutch still frictionally set. Again the clutches are all released when the detent 100 engages in the notch a and still further when the lever is ,moved to bring the detent .100 carried thereby into the notch 101, the highest. speed forward driving gearing is frictionally in clutch which may be followed by theaddh.

tional positive lock clutching by positioning the lever so that its detent 100 engages in the notch 112.

It is the point or elongated portion. of the cam 94 in coaction with one of the arms of either of the angular levers that is instrumental in setting the proper. one of the clutches frictionally orboth frictionally and positively lockcd,-such cam in operating having through the actuating connections therefor a movement of about it of a revolution. And while the most elongated portion of the cam may be operated to set in clutchany one of the desired clutch devices, the head or rounded portion of 'the camremains. in such a restraining engagement with the lever opposite. the one the cam point engages as to assure that the other clutches must for the time and until wilfully and ppsitively operated remain open.

'lhecontrolling means illustrated in Fig. 10 1s s'1mple, capabl e of belng operated for a protracted time without material wear or derangement, and is operatively reliable; but certain departments of this invention are not dependent necessarily on having this particular controlling mechanism combined therewith.

I claim 1.' in a variable speed transmission mechanism, a transmission-shaft and a countershaft, a circular clutch member rotatively I free on the transmission shaft, gearing con"- necting the countershaft and said clutch member, a support mounted on and non-rotative relatively to the transmission shaft and carrying a fellow clutch member for coaction with the said first clutch member, a collar,

having a clutch device operating member, a

slide movable parallel with the transmission shaft, having a member engaging for end wise movements, only, the said collar, a rock variable speed gearin in sets connecting the countershaft and sai clutch. members, supports mounted on and non-rotative relatively to the transmission shaft and each carrying fellow clutch devices for coac tion with the said clutch members, collars, one of each lo cated between a pair of the clutch members having clutch device operating members, slides movable parallel with the transmission shaft having members engaging for endwise movements,.only, the said collars, oppositely located rock shafts having arms engaging said slides and having angular levers, a rcvoluble cam located between said angular levers and coacting with both thereof, and means for positioning said cam. and correspondingly positioning the said collars.

3 In a variable speed transmission rnechanism, a transmission shaft and a countershaft, a plurality of circular clutch members rotative'ly free on the transmission. shaft,

countershaft and said clutch members, sup.-

ports mounted on and non-rotative relatively to the transmission shaft and each carrying contributory clutch devices for coaction with the said cl'iitch members, collars, one of each located between a pair ofthe clutch members having clutch device operating members, slides movable parallel with the transmission shaft having members engaging for endwise movements, only, the said collars, op-

positely located rock shafts having arms engaging said slides and having angular levers, a rotative shaft having a cam located be- .tWeen said angular levers and coacting with ports mounted on and non-rotative relatively" to the transmission shaft and each carrying contributory clutch devices for coaction with the said clutch members, collars, one of each located between a pair of the clutch members having clutch device operating members, slides movable parallel with the transmission shaft having members engaging for endwise movements, only, the said collars, located rock shafts having arms engaging said slides and having angular levers, a rotw tive shaft having a cam located between said angular leversand coacting with both thereof, and a pinion on said cam sh aft, a sector gear meshing with said pinion, an are shaped plate having detent notches therein, a lever fulcrumed to swing alongside said plate, and

oppositely seems having a spring detent for engagement in said notches, and a link connecting said lever and said sector gear.

5. In a variable speed transmission and controlling mechanism, in combination, two shafts having setsv of differently proportioned gears connecting the one with the other, and each set having appurtenant thereto, a clutch comprising frictional, and positively-locking, clutch members, and means individual to each clutch for placing it free, for placing it frictionally clutched, and for placing it additionally lock clutched, and a controlling lever coacting with the clutch operating meansand so operative that a degree of movementof such lever will first cause a frictional setting of a given'clutch, and a further degree of movement oi such lever will cause the additional positively locking of of said lever in succession releasing one of the clutches, and frictionally, and then positively lock-setting the next clutch.

Signed by me at Boston, Mass. in presence of two subscribing witnesses.

ALBERT LATHAM. li itnesses RICHARD F. lsinnrnr, J. W. Noonnonnn.

the clutch continued movements 

